The days when party machines just fixed things or rigged elections are mercifully done with. The way in which outsider candidates, from Obama to Trump and Sanders, have brought millions of new people into the electoral process is an unmitigated advance. The inclusion of previously excluded voices helps, rather than impedes, our public deliberation. But it is precisely because of the great accomplishments of our democracy that we should be vigilant about its specific, unique vulnerability: its susceptibility, in stressful times, to the appeal of a shameless demagogue.

What the 21st century added to this picture, it’s now blindingly obvious, was media democracy — in a truly revolutionary form. If late-stage political democracy has taken two centuries to ripen, the media equivalent took around two decades, swiftly erasing almost any elite moderation or control of our democratic discourse. The process had its origins in partisan talk radio at the end of the past century. The rise of the internet — an event so swift and pervasive its political effect is only now beginning to be understood — further democratized every source of information, dramatically expanded each outlet’s readership, and gave everyone a platform. All the old barriers to entry — the cost of print and paper and distribution — crumbled.

So much of this was welcome. I relished it myself in the early aughts, starting a blog and soon reaching as many readers, if not more, as some small magazines do. Fusty old-media institutions, grown fat and lazy, deserved a drubbing. The early independent blogosphere corrected facts, exposed bias, earned scoops. And as the medium matured, and as Facebook and Twitter took hold, everyone became a kind of blogger. In ways no 20th-century journalist would have believed, we all now have our own virtual newspapers on our Facebook newsfeeds and Twitter timelines — picking stories from countless sources and creating a peer-to-peer media almost completely free of editing or interference by elites. This was bound to make politics more fluid. Political organizing — calling a meeting, fomenting a rally to advance a cause — used to be extremely laborious. Now you could bring together a virtual mass movement with a single webpage. It would take you a few seconds.

The web was also uniquely capable of absorbing other forms of media, conflating genres and categories in ways never seen before. The distinction between politics and entertainment became fuzzier; election coverage became even more modeled on sportscasting; your Pornhub jostled right next to your mother’s Facebook page. The web’s algorithms all but removed any editorial judgment, and the effect soon had cable news abandoning even the pretense of asking “Is this relevant?” or “Do we really need to cover this live?” in the rush toward ratings bonanzas. In the end, all these categories were reduced to one thing: traffic, measured far more accurately than any other medium had ever done before.

And what mainly fuels this is precisely what the Founders feared about democratic culture: feeling, emotion, and narcissism, rather than reason, empiricism, and public-spiritedness. Online debates become personal, emotional, and irresolvable almost as soon as they begin. Godwin’s Law — it’s only a matter of time before a comments section brings up Hitler — is a reflection of the collapse of the reasoned deliberation the Founders saw as indispensable to a functioning republic.